I just think of if we are considering a triangle ABC, that is we have sides AB, AC and BCwe should remember one thing , that is the sum of 2 sides must larger than the otherthat meansAB+AC>BCbut if we are talking about a lineit does not obeyso i would say a line is not a triangle!

For a ΔABC, where angle ABC = 90̊, angle BCA = 90̊ and angle CAB = 0̊, AB//AC(int. angles supp.), AB = AC(sides opp. equal angles), since parallel lines never meet unless they overlap, but AB and AC meet at A, therefore the two lines overlap each other, and B and C are at the same position, BC = 0. Since AB + BC = AB = AC, therefore ΔABC isn't actually a triangle, as it doesn't obey the triangle inequality. In fact if you try to draw it, it would be a line. Although cos(90̊), sin(90̊) etc. exist, and are equal to 0 and 1, it's just about a line, not a triangle. If you consider that line as a right-angled triangle and find the ratios, they do equal to 0 and 1.

By the way, you are absolutely not "靚仔". If you say that you are 最靚仔既Henry, then you are insulting every person named Henry by saying that they are all extremely ugly, as you say that they are uglier than you.